用毛皮摩擦过的橡胶棒去靠近一个用丝线悬挂着的通草球时，若通草球被吸引，则该通草球（ ）
All the students p____ at the lecture were deeply touched by his success story.
下边是某同学整理的资料卡片。它可用来研究（ ）
